A laminated film in which a thin film layer is formed (laminated) on a surface of a film-like base material in order to impart functionality to the base material is known. For example, a laminated film to which a gas barrier property is imparted by forming a thin film layer on a plastic film is suited for filling and packaging of articles such as foods and beverages, cosmetics, and detergents. In recent years, a laminated film in which a thin film of an inorganic oxide such as silicon oxide, silicon nitride, silicon oxynitride, and aluminum oxide is formed on one of surfaces of a base material film such as a plastic film has been proposed.
As a method for forming a thin film of an inorganic oxide on a surface of a plastic base material, deposition methods including physical vapor deposition (PVD) methods such as a vacuum evaporation method, a sputtering method, and an ion plating method, and chemical vapor deposition (CVD) methods such as a low pressure chemical vapor deposition method and a plasma chemical vapor deposition method are known.
Then, Patent Document 1 and Patent Document 2 each disclose a gas barrier laminated film in which a thin film layer of silicon nitride or silicon carbon oxynitride is formed by the aforementioned methods.